Effects of enriched food with selenium nanoparticles on breeding efficiency of female rainbow trout (Oncorhynchus mykiss)

This research investigated the influence of selenium nanoparticles (SeNPs) on the reproductive performance of female rainbow trout (mykiss Oncorhynchus) broodstocks. A total of 120 female broodstock were selected from breeders of the Shahid Motahary Coldwater Fishes Genetic and Breeding Research Center. After adaptation, fish were divided into four treatments in three replicates. Fish were fed diets containing 0 (control) 0.5, 1 and 2 mg SeNPs per kg of diet for 60 days. Eggs quality parameters such as fecundity, fertilization rate, eyed egg rate, hatching, etc. were evaluated. The highest fertilization rate was observed in fish fed with 2 mg selenium (99.30%), which had a significant difference with control groups (p< 0.05) but did not show any significant difference (p>0.05) with fish fed 0.5 mg and 1 mg SeNPs. Broodstocks fed with 2 mg SeNPs had the highest absolute fecundity, which had a significant difference with groups fed 1 mg SeNPs (p <0.05), but did not show significant difference with other two treatments (p >0.05). ) The highest and the lowest relative fecundity were seen in group fed 2 mg SeNPs and 1 mg SeNPs, respectively. However, there was no significant difference in relative fecundity between treatments (p >0.05). The highest egg diameter was in fish fed 0.5 mg SeNPs. Egg diameter in the control group, fish fed 2 and 1 mg SeNPs, were 5.39, 5.39 and 5.40 mm, respectively). There was no significant difference for egg diameters among gruops (p> 0.05). The highest and the lowest mean total egg weight were in group fed 0.5 mg SeNPs and 1 mg SeNPs, respectively, and no significant differences were observed between treatments (P >0.05). The highest percentage of hatching was observed in groups fed 2 mg SeNPs, which had a significant difference with other treatments (p <0.05). The highest survival rate was observed in groups fed 2 mg SeNPs too, which showed no significant difference with other treatments (p >0.05). Increase in the survival rate associated with an increase in the concentration of SeNPs. In general, inclusion of SeNPs in diet, improve the quality and quantity of eggs and reproductive function (fertilization, eyed rate and hatching) in rainbow trout breeders.